FPCs deliver critical 60% weight saving over wire harness for power and control

Trackwise has shipped a 26 meter long multilayer, flexible printed circuit (FPC), believed to be world’s longest ever produced, for distributing power and control signals across the wings of a solar-powered, unmanned aerial vehicle (UAV). The circuit is one of over fifty supplied by Trackwise into this vehicle.

The entire interconnect system (power and signal) of the vehicle is made of FPCs representing an estimated total systems weight saving of 60% over traditional wire harness. This will enable the UAV, which is being manufactured in the US, to achieve higher payload and/or improved speed and range. The FPCs are manufactured using Improved Harness Technology™ (IHT), a patented, reel-to-reel manufacturing technique. Conventional FPCs are rarely more than two metres in length, primarily due to limitations of manufacturing processes. IHT overcomes these limitations, enabling FPCs of unlimited length to be produced.

The UAV’s flexible circuit is based on a polyimide substrate. The planar structure of the circuit dissipates heat better than conventional wiring, enabling higher current carrying capacity for a given weight of copper conductor. Printed manufacturing ensures circuit consistency, fewer connection points are needed so reliability is enhanced, and the FPC is easier to install than wire harnesses, reducing a vehicle’s assembly time and cost.

Trackwise CEO, Philip Johnston, said: “There are many new applications emerging for long, lightweight FPCs but aerospace is a natural fit: weight savings, high reliability and cost effectiveness are critical. We’re also seeing growing interest from a variety of sectors including medical and automotive. For the latter, manufacturers are challenged to reduce vehicle weight to improve fuel efficiency at a time when there’s an ever-growing array of electrical and electronic circuits in their vehicles. In particular, electric vehicles are accelerating this trend.”